I had a skein of Handmaiden Lace Silk - 900m worth of laceweight - that was fine until the last 100m or so, then I had to spend two hours untangling it while somehow trying to keep my cat from giving in to temptation... I truly feel your pain.

Strange as it seems, I sometimes enjoy working out the tangles. It can almost be soothing...or at least I tell myself that it is! ;) Maybe it makes me feel like I'm doing some "cleaning up" and not avoiding housework with my knitting.